A wide range of “keyless” security systems exist, including remote controlled gate operators and the like for residential, industrial, and/or business installations. Depending on the installation and circumstances, a large number of users may need to pass through a given entry on a regular basis. Similarly, in certain circumstances, there may be a substantial turnover or addition to the number or identity of users needing access (or having authorized access) during any given period of time. For example, employment changes, expansion, and similar factors can affect the number and identity of persons needing access through a particular company's entry gate, door, barrier arm, turnstile, or any other access control point.
In many applications, such systems include multiple transmitters (one is given to each authorized user), each of which activates a single receiver. Transmitters can take many forms, including (without limitation) cards, handheld electronic keys, RF or other frequency button activated devices, etc. The receiver is typically located at or near the controlled gate or door and, upon receiving an appropriate signal from any such transmitter, the receiver activates (typically opens or unlocks) the gate or door.
Security of such entries is improved by providing user-specific remote controls a unique, identifiable transmitter/controller for each user. That improved security normally comes at some cost, in that such user-specific controls can be burdensome to program, use, and administer, if they are available at all.
Such systems vary widely in their complexity and consequent degree of security. For example, transmitters commonly range from 256 code combinations (using eight DIP switches) to 65,536 code combinations (using 16 bit keys).
Criminals or other persons have attacked security system technologies with technologies of their own. Among other things, these counter-efforts include code breakers such as code scanners (signal-generating devices that can generate a massive series of signals, one of which may be the “correct” signal that activates the security system's receiver), and code grabbers (which can surreptitiously record a signal as it is generated by an authorized user, and can subsequently re-emit that identical signal). Such counter-efforts can seriously compromise the security of certain systems.
Later generation security systems attempted to address those counter-technologies. One such effort was to utilize 32-bit keys to increase the number of code combinations. However, this increase in bit keys only added to the number to combinations that a code scanner had to try before the right combination was “cracked.” Against a code grabber, this increase provided no additional protection.
Rotating code or code hopping security systems address the problem by utilizing code generators to produce different signals each time a transmitter emits a signal. With the addition of encryption and a 64-bit transmission length, such systems have substantially improved security. “Unique” identifying information is typically “burned” into each transmitter's internal chips or circuitry, and that information can be used within the security system not only to control which transmitters are “authorized” to open a gate (by way of example), but even to track and log which transmitters were in fact used at which time(s). Examples of such improved technology are discussed in U.S. Pat. Nos. 5,517,187 and 5,686,904. Commonly, that “unique” information is part of the signal that is transmitted to the receiver in order to activate the gate, door, etc.
Typically, for these systems to be-effective, the system administrator has to control and track the distribution of the transmitters, but that commonly involves only two actions: an initial “check-out” (when the transmitter is given to the user/tenant) and subsequent “check-in” (such as when the tenant turns in his or her keys/controllers/etc. upon terminating their lease). In the event of some intervening problem, however, such control and tracking of users and their respective transmitters can enable the manager/owner to “disable” the transmitter (even though it has not been returned to the manager/owner) by removing its “identification” from the list of authorized users within the receiver. This “authorized list” is a control level that is independent of the “learning” process required for each transmitter. Even if a transmitter is “learned” into the receiver, this further control can override and prevent activation of the gate or door based on that “unique” identification information in the transmitter.
Newer 64-bit technology has now raised the number of unique code combinations into the billions, and is further secured when combined with the aforementioned rotating code and encryption technologies. Against such systems, contemporary code scanners and code grabbers are ineffective, and at least currently, this type of security system is extremely difficult (or even virtually impossible) to “crack”. Foreseeably, further advances in computer technology and manufacture will increase those combinations even further and may add additional “security” aspects to the technology.
Despite their advantages, conventional rotating code or code hopping security systems have some shortcomings. Among other things, they can be difficult or burdensome to administer when there are multiple users and/or there is turnover among the users. This difficulty arises at least in part from the fact that each transmitter (with its “unique” identifying code or other unique information) typically must be “learned” into the receiver (see, e.g., U.S. Pat. No. 5,686,904) before the transmitter is operational. In this “learn” process, a button or several buttons on the receiver are manually pushed, which switches the receiver from normal operation to “learn” mode. While the receiver is in that “learn” mode, the transmitter that is to be “learned” is then aimed towards the receiver and its transmit button pushed. The transmitter emits and the receiver receives a 64-bit or other signal which contains various sub-signals or information (such as a synchronization signal, a button signal, facility code signal, etc.). Once that transmitter's signal is received, compared, and processed, the transmitter is “activated” and available for future use (in effect, the receiver side of the system will thereafter recognize that unique transmitter and its signals as “authorized”). This “learning” process must be repeated for each other transmitter before those other transmitters will activate the receiver.
Consequently, and as indicated above, despite the benefits of this rotating code or code hopping technology, it can be cumbersome to administer in a large user situation. For example, if such a system is used in an apartment or business complex, each tenant's transmitter must be “manually” learned or programmed before the tenant can use it. Such transmitters are used, for example, to open a common gate that permits entry into an apartment complex parking or common areas. Under this scenario, either each tenant must be taught how to program or “learn” his transmitter into the receiver, or the management/owner of the complex must do so for each tenant/transmitter. If there is a power failure, the “learning” can be lost from the receiver (unless flash memory, emergency backup power sources, permanent memory, or similar technology is provided), which requires that all transmitters to be relearned. Even if permanent memory is used, however, other failure of the receiver or access control system can require that all the transmitters be relearned into the replacement equipment. During any such period of inoperability (not only during the power outage itself, but during any period of time required to “relearn” the transmitters), access to the complex can either be precluded (even for tenants that are authorized to enter) or uncontrolled (such as if the gate is left open to prevent a massive number of frustrated tenants from not being able to enter the complex).
Other problems can occur in such multi-user systems, such as when one tenant or user tries to enter through the gate while another transmitter is being “learned”. Also, if the apartment manager or owner programs in or “learns” all the transmitters himself, he could be programming hundreds or even thousands of transmitters, a very daunting task.